3D-wound healing model: influence of morphine and solid lipid nanoparticles

Hospitalized Cancer Patients with Opioid Management for Chemo-Induced Ulcerative Mucositis Lessens the Patients' Overall Burden of Illness

Objectives: Mucositis is a debilitating side effect of cancer therapy that adversely affects quality of life, cost of care, and the outcome of cancer therapy. Oral mucositis-related pain may be treated with numerous modalities but often includes opioids. The effects of opiate treatment on painful UM and its overall influence on the burden of illness (BOI) in cancer patients remain unknown. Methods: This study utilized the 2017 United States (US) National Inpatient Sample (NIS) database. The exposure was opioid treatment for chemo-induced ulcerative mucositis (UM), oral mucositis-induced pain, and the main outcomes included in-hospital mortality and BOI, length of hospital stays (LOS), and total hospital charges. Multivariable regression analysis was used to examine the relationship between outcomes and the key independent variable, opioid use, adjusting for propensity scores. Results: In the propensity score-adjusted analysis, UM patients with opioid treatment had 0.51 times lower total charges (95% CI: 0.42-0.76) and 0.67 times shorter LOS (95% CI: 0.51-0.87) than the UM patients without opioid treatment. However, there was no association between opioid treatment and in-hospital mortality. In the sensitivity analysis, the effect estimates were comparable in the propensity score-adjusted analysis, the decile-adjusted model, and the full model with the non-propensity score estimated method. Conclusions: Cancer patients with chemotherapy-induced UM-prescribed opioid analgesics for treating pain are associated with a lower BOI. Opioid pain medications are commonly provided to cancer survivors; estimating the BOI among them is crucial in supportive care research.

Non-analgesic effects of opioids: Topical application of Eucerin-based ointment containing opium on the healing process of thermal skin damage in rats

The present study aimed to investigate the efficacy of different doses of Eucerin-based ointment containing opium compared to routine treatment on experimentally induced burn injury. Male Wistar rats were divided into five experimental groups for topical application: silver sulfadiazine 1% (SSD), Eucerin-based ointment containing opium at concentrations of 0.05%, 0.5%, and 5%, and a Eucerin-based ointment containing 0.05% opium plus SSD (mixed group), following burn wound induction using the comb burn model. An equal volume of different ointments was administered topically. The wound appearances of different groups were photographed at different time points for 21 days. In addition, blood and skin samples were taken 2 and 10 days after thermal injury to assess inflammatory parameters and oxidative stress markers. Also, the liver enzyme activity and kidney function tests were assessed on day 10. The body weight in Opium 5% significantly decreased compared to all other groups after ten days. The wound area was significantly reduced (P<0.05) in three groups: Opium 0.05%, Opium 0.5%, and mixed, compared to the SSD group on days 14 and 21. On day 21, the wound size in the Opium 5% group was significantly larger than that in the SSD group. Significantly lower serum levels of MDA were observed in all groups compared to the SSD group on days 2 and 10. There were no significant differences between treatment groups for concentrations of TNF-α in serum and burned skin samples (p>0.05). The serum concentrations of interleukin-10 in the mixed group were significantly higher compared to the SSD group on day 10. After ten days, groups were not different regarding AST, ALT, and creatinine concentrations (p>0.05). Histopathological analysis revealed that the wound healing efficacy of opium at its lowest concentration (0.05%) surpassed that of silver sulfadiazine (SSD). Furthermore, the combination of 0.05% opium with SSD enhanced the wound repair potential of SSD in burn injuries. This study showed that opium ointment delayed wound closure dose-dependently. Low doses of topical opium ointment and its mixed application with silver sulfadiazine had a protective role in thermal-induced injury.

Potential of nanoemulsions for accelerated wound healing: innovative strategies

Wounds represent various significant health concerns for patients and also contribute major costs to healthcare systems. Wound healing comprises of overlapped and various coordinated steps such as homeostasis, inflammation, proliferation, and remodeling. In response to the failure of many strategies in delivering intended results including wound closure, fluid loss control, and exhibiting properties such as durability, targeted delivery, accelerated action, along with histocompatibility, numerous nanotechnological advances have been introduced. To understand the magnitude of wound therapy, this systematic and updated review discussing the effectiveness of nanoemulsions has been undertaken. This review portrays mechanisms associated with wound healing, factors for delayed wound healing, and various technologies utilized to treat wounds effectively. While many strategies are available, nanoemulsions have attracted the tremendous attention of scientists globally for the research in wound therapy due to their long-term thermodynamic stability and bioavailability. Nanoemulsions not only aid in tissue repair, but are also considered as an excellent delivery system for various synthetic and natural actives. Nanotechnology provides several pivotal benefits in wound healing, including improved skin permeation, controlled release, and stimulation of fibroblast cell proliferation. The significant role of nanoemulsions in improved wound healing along with their preparation techniques has also been highlighted with special emphasis on mechanistic insights. This article illustrates recent research advancements for the utilization of nanoemulsions in wound treatment. An adequate literature search has been conducted using the keywords 'Nanoemulsions in wound healing', 'Wound therapy and nanoemulsions', 'Herbal actives in wound therapy', 'Natural oils and wounds treatment' etc., from PubMed, Science Direct, and Google Scholar databases. Referred and original publications in the English language accessed till April 2022 has been included, whereas nonEnglish language papers, unpublished data, and nonoriginal papers were excluded from the study.

Skin models of cutaneous toxicity, transdermal transport and wound repair

Skin is widely used as a drug delivery route due to its easy access and the possibility of using relatively painless methods for the administration of bioactive molecules. However, the barrier properties of the skin, along with its multilayer structure, impose severe restrictions on drug transport and bioavailability. Thus, bioengineered models aimed at emulating the skin have been developed not only for optimizing the transdermal transport of different drugs and testing the safety and toxicity of substances but also for understanding the biological processes behind skin wounds. Even though in vivo research is often preferred to study biological processes involving the skin, in vitro and ex vivo strategies have been gaining increasing relevance in recent years. Indeed, there is a noticeably increasing adoption of in vitro and ex vivo methods by internationally accepted guidelines. Furthermore, microfluidic organ-on-a-chip devices are nowadays emerging as valuable tools for functional and behavioural skin emulation. Challenges in miniaturization, automation and reliability still need to be addressed in order to create skin models that can predict skin behaviour in a robust, high-throughput manner, while being compliant with regulatory issues, standards and guidelines. In this review, skin models for transdermal transport, wound repair and cutaneous toxicity will be discussed with a focus on high-throughput strategies. Novel microfluidic strategies driven by advancements in microfabrication technologies will also be revised as a way to improve the efficiency of existing models, both in terms of complexity and throughput.

Combinational System of Lipid-Based Nanocarriers and Biodegradable Polymers for Wound Healing: An Updated Review

Skin wounds have imposed serious socioeconomic burdens on healthcare providers and patients. There are just more than 25,000 burn injury-related deaths reported each year. Conventional treatments do not often allow the re-establishment of the function of affected regions and structures, resulting in dehydration and wound infections. Many nanocarriers, such as lipid-based systems or biobased and biodegradable polymers and their associated platforms, are favorable in wound healing due to their ability to promote cell adhesion and migration, thus improving wound healing and reducing scarring. Hence, many researchers have focused on developing new wound dressings based on such compounds with desirable effects. However, when applied in wound healing, some problems occur, such as the high cost of public health, novel treatments emphasizing reduced healthcare costs, and increasing quality of treatment outcomes. The integrated hybrid systems of lipid-based nanocarriers (LNCs) and polymer-based systems can be promising as the solution for the above problems in the wound healing process. Furthermore, novel drug delivery systems showed more effective release of therapeutic agents, suitable mimicking of the physiological environment, and improvement in the function of the single system. This review highlights recent advances in lipid-based systems and the role of lipid-based carriers and biodegradable polymers in wound healing.

Different Curcumin-Loaded Delivery Systems for Wound Healing Applications: A Comprehensive Review

Curcumin or turmeric is the active constituent of Curcuma longa L. It has marvelous medicinal applications in many diseases. When the skin integrity is compromised due to either acute or chronic wounds, the body initiates several steps leading to tissue healing and skin barrier function restoration. Curcumin has very strong antibacterial and antifungal activities with powerful wound healing ability owing to its antioxidant activity. Nevertheless, its poor oral bioavailability, low water solubility and rapid metabolism limit its medical use. Tailoring suitable drug delivery systems for carrying curcumin improves its pharmaceutical and pharmacological effects. This review summarizes the most recent reported curcumin-loaded delivery systems for wound healing purposes, chiefly hydrogels, films, wafers, and sponges. In addition, curcumin nanoformulations such as nanohydrogels, nanoparticles and nanofibers are also presented, which offer better solubility, bioavailability, and sustained release to augment curcumin wound healing effects through stimulating the different healing phases by the aid of the small carrier.

Assessing the interactions between nanoparticles and biological barriers in vitro: a new challenge for microscopy techniques in nanomedicine

Nanoconstructs intended to be used as biomedical tool must be assessed for their capability to cross biological barriers. However, studying in vivo the permeability of biological barriers to nanoparticles is quite difficult due to the many structural and functional factors involved. Therefore, the in vitro modeling of biological barriers -2D cell monocultures, 2D/3D cell co-cultures, microfluidic devices- is gaining more and more relevance in nanomedical research. Microscopy techniques play a crucial role in these studies, as they allow both visualizing nanoparticles inside the biological barrier and evaluating their impact on the barrier components. This paper provides an overview of the various microscopical approaches used to investigate nanoparticle translocation through in vitro biological barrier models. The high number of scientific articles reported highlights the great contribution of the morphological and histochemical approach to the knowledge of the dynamic interactions between nanoconstructs and the living environment.

Accelerating skin regeneration and wound healing by controlled ROS from photodynamic treatment

Cellular metabolisms produce reactive oxygen species (ROS) which are essential for cellular signaling pathways and physiological functions. Nevertheless, ROS act as “double-edged swords” that have an unstable redox balance between ROS production and removal. A little raise of ROS results in cell proliferation enhancement, survival, and soft immune responses, while a high level of ROS could lead to cellular damage consequently protein, nucleic acid, and lipid damages and finally cell death. ROS play an important role in various pathological circumstances. On the contrary, ROS can show selective toxicity which is used against cancer cells and pathogens. Photodynamic therapy (PDT) is based on three important components including a photosensitizer (PS), oxygen, and light. Upon excitation of the PS at a specific wavelength, the PDT process begins which leads to ROS generation. ROS produced during PDT could induce two different pathways. If PDT produces control and low ROS, it can lead to cell proliferation and differentiation. However, excess production of ROS by PDT causes cellular photo damage which is the main mechanism used in cancer treatment. This review summarizes the functions of ROS in living systems and describes role of PDT in production of controllable ROS and finally a special focus on current ROS-generating therapeutic protocols for regeneration and wound healing.

In Vitro Models of Biological Barriers for Nanomedical Research

Nanoconstructs developed for biomedical purposes must overcome diverse biological barriers before reaching the target where playing their therapeutic or diagnostic function. In vivo models are very complex and unsuitable to distinguish the roles plaid by the multiple biological barriers on nanoparticle biodistribution and effect; in addition, they are costly, time-consuming and subject to strict ethical regulation. For these reasons, simplified in vitro models are preferred, at least for the earlier phases of the nanoconstruct development. Many in vitro models have therefore been set up. Each model has its own pros and cons: conventional 2D cell cultures are simple and cost-effective, but the information remains limited to single cells; cell monolayers allow the formation of cell–cell junctions and the assessment of nanoparticle translocation across structured barriers but they lack three-dimensionality; 3D cell culture systems are more appropriate to test in vitro nanoparticle biodistribution but they are static; finally, bioreactors and microfluidic devices can mimicking the physiological flow occurring in vivo thus providing in vitro biological barrier models suitable to reliably assess nanoparticles relocation. In this evolving context, the present review provides an overview of the most representative and performing in vitro models of biological barriers set up for nanomedical research.

Efficacy and Safety of Topical Morphine: A Narrative Review

Background. Opioids are the cornerstone of the therapy used in both acute and chronic pain syndromes to treat pain of moderate to severe intensity. The knowledge that opioid receptors also occur in other tissues outside the central nervous system has created a possibility for the topical use of opioids. Thus, local analgesia may be obtained without systemic adverse effects. Methods. A narrative review of scientific papers discussing the topical use of morphine was conducted. For this purpose, the PubMed, Google Scholar, Cochrane Library, and Mendeley databases were searched. Results. The current knowledge on topical morphine does not allow for its recommended use in everyday medical practice, but suggests it may be effective, particularly in the treatment of ulcers and erosions of inflammatory etiology and painful skin lesions including persistent post-mastectomy pain due to breast cancer. Conclusions. Topical morphine has its place beside other analgesics. An important issue is the practical possibility to meet the demand for topical formulations, which is limited by technical difficulties.

Recent advances in pain management based on nanoparticle technologies

BACKGROUND

Pain is a vital sense that indicates the risk of injury at a particular body part. Successful control of pain is the principal aspect in medical treatment. In recent years, the advances of nanotechnology in pain management have been remarkable. In this review, we focus on literature and published data that reveal various applications of nanotechnology in acute and chronic pain management.

METHODS

The presented content is based on information collected through pain management publications (227 articles up to April 2021) provided by Web of Science, PubMed, Scopus and Google Scholar services.

RESULTS

A comprehensive study of the articles revealed that nanotechnology-based drug delivery has provided acceptable results in pain control, limiting the side effects and increasing the efficacy of analgesic drugs. Besides the ability of nanotechnology to deliver drugs, sophisticated nanosystems have been designed to enhance imaging and diagnostics, which help in rapid diagnosis of diseases and have a significant impact on controlling pain. Furthermore, with the development of various tools, nanotechnology can accurately measure pain and use these measurements to display the efficiency of different interventions.

CONCLUSIONS

Nanotechnology has started a new era in the pain management and many promising results have been achieved in this regard. Nevertheless, there is still no substantial and adequate act of nanotechnology in this field. Therefore, efforts should be directed to broad investigations.

Carbon-Based Nanomaterials: Carbon Nanotubes, Graphene and Fullerenes in Control of Burns Infections and Wound Healing

Burn injuries are extremely debilitating, resulting in high morbidity and mortality rates around the world. The risk of infection escalates in correlation with impairment of skin integrity, creating a barrier to healing and possibly leading to sepsis. With its numerous advantages over traditional treatment methods, nanomaterial-based wound healing has immense capability for treating and preventing wound infections. Carbon-based nanomaterials (CNMs) owing to their distinctive physicochemical and biological properties have emerged as promising platform for biomedical applications. Carbon nanotubes, graphene, fullerenes, and their nanocomposites have demonstrated broad antimicrobial activity against invasive bacteria, fungi, and viruses causing burn wound infection. The specific mechanisms that govern the antimicrobial activity of CNMs must be understood in order to ensure the safe and effective incorporation of these structures into biomaterials. However, it is challenging to decouple individual and synergistic contributions of physical, chemical, and electrical effects of CNMs on cells. This review reported on significant advances in the application of CNMs in burn wound infection and wound healing, with brief discussion on the interaction between different families of CNMs and microorganisms to assess antimicrobial performance.

Nanomaterials for application in wound Healing: current state-of-the-art and future perspectives

Nanoparticles are the gateway to the new era in drug delivery of biocompatible agents. Several products have emerged from nanomaterials in quest of developing practical wound healing dressings that are nonantigenic, antishear stress, and gas-exchange permeable. Numerous studies have isolated and characterised various wound healing nanomaterials and nanoproducts. The electrospinning of natural and synthetic materials produces fine products that can be mixed with other wound healing medications and herbs. Various produced nanomaterials are highly influential in wound healing experimental models and can be used commercially as well. This article reviewed the current state-of-the-art and briefly specified the future concerns regarding the different systems of nanomaterials in wound healing (i.e., inorganic nanomaterials, organic and hybrid nanomaterials, and nanofibers). This review may be a comprehensive guidance to help health care professionals identify the proper wound healing materials to avoid the usual wound complications.

Nanotechnology-based therapeutic applications: in vitro and in vivo clinical studies for diabetic wound healing

Diabetic wounds often indicate chronic complications that are difficult to treat. Unfortunately, existing conventional treatment modalities often cause unpremeditated side effects, given the need to develop alternative therapeutic phenotypes that are safe or have minimal side effects and risks. Nanotechnology-based platforms, including nanotherapeutics, nanoparticles (NPs), nanofibers, nanohydrogels, and nanoscaffolds, have garnered attention for their groundbreaking potential to decipher the biological environment and offer personalized treatment methods for wound healing. These nanotechnology-based platforms can successfully overcome the impediments posed by drug toxicity, existing treatment modalities, and the physiology and complexity of the wound sites. Furthermore, studies have shown that they play an essential role in influencing angiogenesis, collagen production, and extracellular matrix (ECM) synthesis, which are integral in skin repair mechanisms. In this review, we emphasized the importance of various nanotechnology-based platforms for healing diabetic wounds and report on the innovative preclinical and clinical outcomes of different nanotechnology-based platforms. This review also outlined the limitations of existing conventional treatment modalities and summarized the physiology of acute and chronic diabetic wounds.

Future roles of artificial intelligence in early pain management of newborns

The advent of increasingly sophisticated medical technology, surgical interventions, and supportive healthcare measures is raising survival probabilities for babies born premature and/or with life-threatening health conditions. In the United States, this trend is associated with greater numbers of neonatal surgeries and higher admission rates into neonatal intensive care units (NICU) for newborns at all birth weights. Following surgery, current pain management in NICU relies primarily on narcotics (opioids) such as morphine and fentanyl (about 100 times more potent than morphine) that lead to a number of complications, including prolonged stays in NICU for opioid withdrawal. In this paper, we review current practices and challenges for pain assessment and treatment in NICU and outline ongoing efforts using Artificial Intelligence (AI) to support pain- and opioid-sparing approaches for newborns in the future. A major focus for these next-generation approaches to NICU-based pain management is proactive pain mitigation (avoidance) aimed at preventing harm to neonates from both postsurgical pain and opioid withdrawal. AI-based frameworks can use single or multiple combinations of continuous objective variables, that is, facial and body movements, crying frequencies, and physiological data (vital signs), to make high-confidence predictions about time-to-pain onset following postsurgical sedation. Such predictions would create a therapeutic window prior to pain onset for mitigation with non-narcotic pharmaceutical and nonpharmaceutical interventions. These emerging AI-based strategies have the potential to minimize or avoid damage to the neonate's body and psyche from postsurgical pain and opioid withdrawal.

Recent perspectives of nanotechnology in burn wounds management: a review

OBJECTIVE

The burden of the management of problematic skin wounds characterised by a compromised skin barrier is growing rapidly. Almost six million patients are affected in the US alone, with an estimated market of $25 billion annually. There is an urgent requirement for efficient mechanism-based treatments and more efficacious drug delivery systems. Novel strategies are needed for faster healing by reducing infection, moisturising the wound, stimulating the healing mechanisms, speeding up wound closure and reducing scar formation.

METHODS

A systematic review of qualitative studies was conducted on the recent perspectives of nanotechnology in burn wounds management. Pubmed, Scopus, EMBASE, CINAHL and PsychINFO databases were all systematically searched. Authors independently rated the reporting of the qualitative studies included. A comprehensive literature search was conducted covering various resources up to 2018-2019. Traditional techniques aim to simply cover the wound without playing any active role in wound healing. However, nanotechnology-based solutions are being used to create multipurpose biomaterials, not only for regeneration and repair, but also for on-demand delivery of specific molecules. The chronic nature and associated complications of nonhealing wounds have led to the emergence of nanotechnology-based therapies that aim at facilitating the healing process and ultimately repairing the injured tissue.

CONCLUSION

Nanotechnology-based therapy is in the forefront of next-generation therapy that is able to advance wound healing of hard-to-heal wounds. In this review, we will highlight the developed nanotechnology-based therapeutic agents and assess the viability and efficacy of each treatment. Herein we will explore the unmet needs and future directions of current technologies, while discussing promising strategies that can advance the wound-healing field.

Applications of Nanosized-Lipid-Based Drug Delivery Systems in Wound Care

Impaired wound healing is an encumbering public health issue that increases the demand for developing new therapies in order to minimize health costs and enhance treatment efficacy. Available conventional therapies are still unable to maximize their potential in penetrating the skin at the target site and accelerating the healing process. Nanotechnology exhibits an excellent opportunity to enrich currently available medical treatments, enhance standard care and manage wounds. It is a promising approach, able to address issues such as the permeability and bioavailability of drugs with reduced stability or low water solubility. This paper focuses on nanosized-lipid-based drug delivery systems, describing their numerous applications in managing skin wounds. We also highlight the relationship between the physicochemical characteristics of nanosized, lipid-based drug delivery systems and their impact on the wound-healing process. Different types of nanosized-lipid-based drug delivery systems, such as vesicular systems and lipid nanoparticles, demonstrated better applicability and enhanced skin penetration in wound healing therapy compared with conventional treatments. Moreover, an improved chemically and physically stable drug delivery system, with increased drug loading capacity and enhanced bioavailability, has been shown in drugs encapsulated in lipid nanoparticles. Their applications in wound care show potential for overcoming impediments, such as the inadequate bioavailability of active agents with low solubility. Future research in nanosized-lipid-based drug delivery systems will allow the achievement of increased bioavailability and better control of drug release, providing the clinician with more effective therapies for wound care.

Nanostructured lipid carriers containing chitosan or sodium alginate for co-encapsulation of antioxidants and an antimicrobial agent for potential application in wound healing

The high incidence and costs of chronic wounds in the elderly have motivated the search for innovations to improve product performance and the healing process while reducing costs. In this study, bioadhesive nanostructured lipid carriers (NLC) were developed for the co-encapsulation of compounds with antioxidant (α-tocopherol and quercetin) and antimicrobial (tea tree oil) activity for management of wounds. The NLC was produced with shea butter and argan oil, and modified with sodium alginate or chitosan to confer bioadhesive properties. Spherical nanoparticles of ~307-330 nm and zeta potential varying from -21.2 to +11.8 mV were obtained. Thermal analysis demonstrated that the lipid matrix reduced tea tree oil thermal loss (~1.8-fold). Regardless of the type of polysaccharide employed, the NLCs promoted cutaneous localization of antioxidants in damaged (subjected to incision) skin, with a ~74 to 180-fold higher delivery into the skin compared to percutaneous delivery. This result is consistent with the similar bioadhesive properties of chitosan or sodium alginate-modified NLC. Nanoencapsulation of tea tree oil did not preclude its antimicrobial effects against susceptible and resistant strains of S. aureus and P. aeruginosa, while co-encapsulation of antioxidants increased the NLC-induced fibroblasts migration, supporting their potential usefulness for management of wounds.

Nanomaterials Versus The Microbial Compounds With Wound Healing Property

Age and diabetes related slow-healing or chronic wounds may result in morbidity and mortality through persistent biofilms infections and prolonged inflammatory phase. Nano-materials [metal/metal oxide NPs (39%), lipid vehicles (21%), polymer NPs (19%), ceramic nanoparticles (NPs) (14%), and carbon nanomaterials (NMs) (7%)] can be introduced as a possible next-generation therapy because of either their intrinsic wound healing activity or via carrying bioactive compounds including, antibiotics, antioxidants, growth factor or stem cell. The nanomaterials have been shown to implicate in all four stages of wound healing including hemostasis (polymer NPs, ceramic NPs, nanoceria-6.1%), inflammation (liposome/vesicles/solid lipid NPs/polymer NPs/ceramic NPs/silver NPs/gold NPs/nanoceria/fullerenes/carbon-based NPs-32.7%), proliferation (vesicles/liposome/solid lipid NPs/gold NPs/silver NPs/iron oxide NPs/ceramic NPs/copper NPs/self-assembling elastin-like NPs/nanoceria/micelle/dendrimers/polymer NPs-57.1%), remodeling (iron oxide NPs/nanoceria-4.1%). Natural compounds from alkaloids, flavonoids, retinoids, volatile oil, terpenes, carotenoids, or polyphenolic compounds with proven antioxidant, anti-inflammatory, immunomodulatory, or antimicrobial characteristics are also well known for their potential to accelerate the wound healing process. In the current paper, we survey the potential and properties of nanomaterials and microbial compounds in improving the process of wound and scar healing. Finally, we review the potential biocompounds for incorporation to nano-material in perspective to designate more effective or multivalent wound healing natural or nano-based drugs.

β-Neoendorphin Enhances Wound Healing by Promoting Cell Migration in Keratinocyte

The skin is the largest and a remarkably plastic organ that serves as a protective barrier against environmental stimuli and injuries throughout life. Skin injuries are serious health problems, and wound healing is a critical process to replace devitalized cellular and tissue structures. Although some endogenous opioids are known to be involved in the modulation of wound healing, it remains to be determined whether the β-neoendorphin (β-NEP), an endogenous opioid, has beneficial effects on wound repair in human keratinocyte. In this study, we found that β-NEP accelerated wound repair through activation of mitogen-activated protein kinase (MAPK)/Erk1/2 signaling pathways in human keratinocytes. Moreover, the wound healing effect of β-NEP is mainly through the acceleration of keratinocyte migration without affecting cell proliferation. Therefore, our studies reveal that β-NEP plays an important role in the regulation of wound repair and suggest a therapeutic strategy to promote wound healing using β-NEP.

Resveratrol Nanoparticles: A Promising Therapeutic Advancement over Native Resveratrol

The importance of fruit-derived resveratrol (RES) in the treatment of various diseases has been discussed in various research publications. Those research findings have indicated the ability of the molecule as therapeutic in the context of in vitro and in vivo conditions. Mostly, the application of RES in in vivo conditions, encapsulation processes have been carried out using various nanoparticles that are made of biocompatible biomaterials, which are easily digested or metabolized, and RES is absorbed effectively. These biomaterials are non-toxic and are safe to be used as components in the biotherapeutics. They are made from naturally available by-products of food materials like zein or corn or components of the physiological system as with lipids. The versatility of the RES nanoparticles in their different materials, working range sizes, specificity in their targeting in various human diseases, and the mechanisms associated with them are discussed in this review.

Bidirectional Regulation of Opioid and Chemokine Function

The opioid family of GPCRs consists of the classical opioid receptors, designated μ-, κ-, and δ-opioid receptors, and the orphanin-FQ receptor, and these proteins are expressed on both neuronal and hematopoietic cells. A number of laboratories have reported that an important degree of cross-talk can occur between the opioid receptors and the chemokine and chemokine receptor families. As a part of this, the opioid receptors are known to regulate the expression of certain chemokines and chemokine receptors, including those that possess strong pro-inflammatory activity. At the level of receptor function, it is clear that certain members of the chemokine family can mediate cross-desensitization of the opioid receptors. Conversely, the opioid receptors are all able to induce heterologous desensitization of some of the chemokine receptors. Consequently, activation of one or more of the opioid receptors can selectively cross-desensitize chemokine receptors and regulate chemokine function. These cross-talk processes have significant implications for the inflammatory response, since the regulation of both the recruitment of inflammatory cells, as well as the sensation of pain, can be controlled in this way.

The future application of nanomedicine and biomimicry in plastic and reconstructive surgery

Plastic surgery encompasses a broad spectrum of reconstructive challenges and prides itself upon developing and adopting new innovations. Practice has transitioned from microsurgery to supermicrosurgery with a possible future role in even smaller surgical frontiers. Exploiting materials on a nanoscale has enabled better visualization and enhancement of biological processes toward better wound healing, tumor identification and viability of tissues, all cornerstones of plastic surgery practice. Recent advances in nanomedicine and biomimicry herald further reconstructive progress facilitating soft and hard tissue, nerve and vascular engineering. These lay the foundation for improved biocompatibility and tissue integration by the optimization of engineered implants or tissues. This review will broadly examine each of these technologies, highlighting areas of progress that reconstructive surgeons may not be familiar with, which could see adoption into our armamentarium in the not-so-distant future.

Characterization of a New Reconstructed Full Thickness Skin Model, T-Skin™, and its Application for Investigations of Anti-Aging Compounds

BACKGROUND

We have characterized a new reconstructed full-thickness skin model, T-Skin™, compared to normal human skin (NHS) and evaluated its use in testing anti-aging compounds.

METHODS

The structure and layer-specific markers were compared with NHS using histological and immunohistological staining. In anti-aging experiments, T-SkinTM was exposed to retinol (10 µM) or vitamin C (200 µM) for 5 days, followed by immunohistological staining evaluation.

RESULTS

T-Skin™ exhibits a well stratified, differentiated and self-renewing epidermis with a dermal compartment of functional fibroblasts. Epidermal (cytokeratin 10, transglutaminase 1), dermo-epidermal junction (DEJ) (laminin 5, collagen-IV, collagen VII) and dermally-located (fibrillin 1, procollagen I) biomarkers were similar to those in NHS. Treatment of T-Skin™ with retinol decreased the expression of differentiation markers, cytokeratin 10 and transglutaminase 1 and increased the proliferation marker, Ki67, in epidermis basal-layer cells. Vitamin C increased the expression of DEJ components, collagen IV and VII and dermal procollagen 1.

CONCLUSIONS

T-Skin™ exhibits structural and biomarker location characteristics similar to NHS. Responses of T-Skin™ to retinol and vitamin C treatment were consistent with those of their known anti-aging effects. T-Skin™ is a promising model to investigate responses of epidermal, DEJ and dermal regions to new skin anti-ageing compounds.

Aspects of Nanomaterials in Wound Healing

Wound infections impose a remarkable clinical challenge that has a considerable influence on morbidity and mortality of patients, influencing the cost of treatment. The unprecedented advancements in molecular biology have come up with new molecular and cellular targets that can be successfully applied to develop smarter therapeutics against diversified categories of wounds such as acute and chronic wounds. However, nanotechnology-based diagnostics and treatments have achieved a new horizon in the arena of wound care due to its ability to deliver a plethora of therapeutics into the target site, and to target the complexity of the normal wound-healing process, cell type specificity, and plethora of regulating molecules as well as pathophysiology of chronic wounds. The emerging concepts of nanobiomaterials such as nanoparticles, nanoemulsion, nanofibrous scaffolds, graphene-based nanocomposites, etc., and nano-sized biomaterials like peptides/proteins, DNA/RNA, oligosaccharides have a vast application in the arena of wound care. Multi-functional, unique nano-wound care formulations have acquired major attention by facilitating the wound healing process. In this review, emphasis has been given to different types of nanomaterials used in external wound healing (chronic cutaneous wound healing); the concepts of basic mechanisms of wound healing process and the promising strategies that can help in the field of wound management.

Perfusable and stretchable 3D culture system for skin-equivalent

This study describes a perfusable and stretchable culture system for a skin-equivalent. The system is comprised of a flexible culture device equipped with connections that fix vascular channels of the skin-equivalent and functions as an interface for an external pump. Furthermore, a stretching apparatus for the culture device can be fabricated using rapid prototyping technologies, which allows for easy modifications of stretching parameters. When cultured under dynamically stretching and perfusion conditions, the skin-equivalent exhibits improved morphology. The epidermal layer becomes thicker and more differentiated than that cultured without the stretching stimuli or under statically-stretched conditions, and the dermal layer was more densely populated with dermal fibroblasts than that cultured without perfusion due to the nutrient and oxygen supply by perfusion via the vascular channels. Therefore, the system is useful for the improvement and biological studies of skin-equivalents.

Opioids: Modulators of angiogenesis in wound healing and cancer

Opioids are potent drugs that are widely used to control wound or cancer pain. Increasing evidence suggest that opioids mediate clinically relevant effects that go beyond their classical role as analgesics. Of note, opioids appear to modulate angiogenesis - a process that is critical in wound healing and cancer progression. In this review, we focus on pro- and anti-angiogenic facets of opioids that arise from the activation of individual opioid receptors and the usage of individual concentrations or application routes. We overview the still incompletely elucidated mechanisms of these angiogenic opioid actions. Moreover, we describe plausible opioids effects, which - although not primarily studied in the context of vessel formation - may be related to the opioid-driven processes of angiogenesis. Finally we discuss the use of opioids as an innovative therapeutic avenue for the treatment of chronic wounds and cancer.

The Roles of Opioid Receptors in Cutaneous Wound Healing

The process of recovery from skin wounding can be protracted and painful, and scarring may lead to weakness of the tissue, unpleasant sensations such as pain or itch, and unfavorable cosmetic outcomes. Moreover, some wounds simply fail to heal and become a chronic burden for the sufferer. Understanding the mechanisms underlying wound healing and the concomitant sensory disorders and how they might be manipulated for therapeutic benefit has attracted much interest in recent years, and here we discuss the latest developments in the field, focusing on the emergent roles of the peripheral opioid receptor (OPr) system.

Nanomedicine and advanced technologies for burns: Preventing infection and facilitating wound healing

According to the latest report from the World Health Organization, an estimated 265,000 deaths still occur every year as a direct result of burn injuries. A widespread range of these deaths induced by burn wound happens in low- and middle-income countries, where survivors face a lifetime of morbidity. Most of the deaths occur due to infections when a high percentage of the external regions of the body area is affected. Microbial nutrient availability, skin barrier disruption, and vascular supply destruction in burn injuries as well as systemic immunosuppression are important parameters that cause burns to be susceptible to infections. Topical antimicrobials and dressings are generally employed to inhibit burn infections followed by a burn wound therapy, because systemic antibiotics have problems in reaching the infected site, coupled with increasing microbial drug resistance. Nanotechnology has provided a range of molecular designed nanostructures (NS) that can be used in both therapeutic and diagnostic applications in burns. These NSs can be divided into organic and non-organic (such as polymeric nanoparticles (NPs) and silver NPs, respectively), and many have been designed to display multifunctional activity. The present review covers the physiology of skin, burn classification, burn wound pathogenesis, animal models of burn wound infection, and various topical therapeutic approaches designed to combat infection and stimulate healing. These include biological based approaches (e.g. immune-based antimicrobial molecules, therapeutic microorganisms, antimicrobial agents, etc.), antimicrobial photo- and ultrasound-therapy, as well as nanotechnology-based wound healing approaches as a revolutionizing area. Thus, we focus on organic and non-organic NSs designed to deliver growth factors to burned skin, and scaffolds, dressings, etc. for exogenous stem cells to aid skin regeneration. Eventually, recent breakthroughs and technologies with substantial potentials in tissue regeneration and skin wound therapy (that are as the basis of burn wound therapies) are briefly taken into consideration including 3D-printing, cell-imprinted substrates, nano-architectured surfaces, and novel gene-editing tools such as CRISPR-Cas.

Current progress and challenges of nanoparticle-based therapeutics in pain management

Pain is a widespread and growing health problem worldwide that exerts a considerable social and economic impact on both patients and healthcare systems and, therefore, on society in general. Although current treatment modalities include a wide variety of pharmacological and non-pharmacological approaches, due to the complexity of pain and individual differences in clinical response these options are not always effective in mitigating and relieving pain. In addition, some pain drugs such as non-steroidal anti-inflammatory drugs (NSAIDs), local anesthetics and opioids show several unfavorable side effects. Therefore, current research advances in this medical field are based on the development of potential treatments to address many of the unmet needs and to overcome the existing limitations in pain management. Nanoparticle drug delivery systems present an exciting opportunity as alternative platforms to improve efficacy and safety of medications currently in use. Herein, we review a broad range of nanoparticle formulations (organic nanostructures and inorganic nanoparticles), which have been developed to encapsulate an array of painkillers, paying special attention to the key advantages that these systems offer, (compared to the use of the free drug), as well as to the more relevant results of preclinical studies in animal models. Additionally, we will briefly discuss the impact of some of these nanoformulations in clinical trials.

Topical application of morphine for wound healing and analgesia in patients with oral lichen planus: a randomized, double-blind, placebo-controlled study

OBJECTIVE

The objective of this study was to investigate the effect of topical morphine on erosive/ulcerative lesions in patients with oral lichen planus (OLP). Previous studies reported on an enhanced remission of skin wounds when morphine was applied topically.

MATERIALS AND METHODS

This was single-center, prospective, double-blind, placebo-controlled, randomized, multi-arm (3), phase II study (RCT). Patients diagnosed with erosive and/or ulcerative OLP applied 0.2 or 0.4 mg morphine dissolved in glycerine, three times a day for 5 days. The primary outcome was the extent of healing. Secondary outcomes were as follows: (1) effect on pain, (2) presence and severity of opioid-related central and local side effects, (3) whether patients required 'rescue medication' for treatment of pain, and (4) total intake of test substance.

RESULTS

A total of 123 patients were screened for eligibility, 45 patients were recruited into the study, and 43 completed it. Patients applied a solution of either placebo or 0.2 or 0.4% morphine in groups of n = 12, n = 15, and n = 16, respectively. Extent of healing was similar in the three groups. Severity of pain was minor pre-treatment and throughout the course of the study. Only minor adverse events were reported (dry mouth, burning sensation).

CONCLUSION

Morphine did not enhance wound healing compared to placebo-treated patients. Healing was observed in all groups, which may be attributed to an effect of glycerine or to the natural course of the disease. Patients experienced only mild levels of pain, rendering the model insensitive for assessing pain.

CLINICAL RELEVANCE

OLP is a chronic disease and current treatment options are limited. Healing occurred in all three study groups, an effect we attribute to the carrier.

Development of functionalized hollow microporous organic capsules encapsulating morphine – an in vitro and in vivo study

Carboxylic group functionalized hollow microporous organic capsules (HMOCs) are synthesized that show extraordinary high encapsulation efficiency of morphine·HCl and its promising prolonged release.

Biomaterials and Nanotherapeutics for Enhancing Skin Wound Healing

Wound healing is an intricate process that requires complex coordination between many cell types and an appropriate extracellular microenvironment. Chronic wounds often suffer from high protease activity, persistent infection, excess inflammation, and hypoxia. While there has been intense investigation to find new methods to improve cutaneous wound care, the management of chronic wounds, burns, and skin wound infection remain challenging clinical problems. Ideally, advanced wound dressings can provide enhanced healing and bridge the gaps in the healing processes that prevent chronic wounds from healing. These technologies have great potential for improving outcomes in patients with poorly healing wounds but face significant barriers in addressing the heterogeneity and clinical complexity of chronic or severe wounds. Active wound dressings aim to enhance the natural healing process and work to counter many aspects that plague poorly healing wounds, including excessive inflammation, ischemia, scarring, and wound infection. This review paper discusses recent advances in the development of biomaterials and nanoparticle therapeutics to enhance wound healing. In particular, this review focuses on the novel cutaneous wound treatments that have undergone significant preclinical development or are currently used in clinical practice.

In vitro models for evaluating safety and efficacy of novel technologies for skin drug delivery

For preclinical testing of novel therapeutics, predictive in vitro models of the human skin are required to assess efficacy, absorption and safety. Simple as well as more sophisticated three-dimensional organotypic models of the human skin emerged as versatile and powerful tools simulating healthy as well as diseased skin states. Besides addressing the demands of research and industry, such models serve as valid alternative to animal testing. Recently, the acceptance of several models by regulatory authorities corroborates their role as important building block for preclinical development. However, valid assessment of readout parameters derived from these models requires suitable analytical techniques. Standard analytical methods are mostly destructive and limited regarding in-depth investigation on molecular level. The combination of adequate in vitro models with modern non-invasive analytical modalities bears a great potential to address important skin drug delivery related questions. Topics of interest are for instance the assessment of repeated dosing effects and xenobiotic biotransformation, which cannot be analyzed by destructive techniques. This review provides a comprehensive overview of current in vitro skin models differing in functional complexity and mimicking healthy as well as diseased skin states. Further, benefits and limitations regarding analytical evaluation of efficacy, absorption and safety of novel drug carrier systems applied to such models are discussed along with a prospective view of anticipated future directions. In addition, emerging non-invasive imaging modalities are introduced and their significance and potential to advance current knowledge in the field of skin drug delivery is explored.

The Burn Wound Microenvironment

Significance: While the survival rate of the severely burned patient has improved significantly, relatively little progress has been made in treatment or prevention of burn-induced long-term sequelae, such as contraction and fibrosis. Recent Advances: Our knowledge of the molecular pathways involved in burn wounds has increased dramatically, and technological advances now allow large-scale genomic studies, providing a global view of wound healing processes. Critical Issues: Translating findings from a large number of in vitro and preclinical animal studies into clinical practice represents a gap in our understanding, and the failures of a number of clinical trials suggest that targeting single pathways or cytokines may not be the best approach. Significant opportunities for improvement exist. Future Directions: Study of the underlying molecular influences of burn wound healing progression will undoubtedly continue as an active research focus. Increasing our knowledge of these processes will identify additional therapeutic targets, supporting informed clinical studies that translate into clinical relevance and practice.

Nanomaterials as a game changer in the management and treatment of diabetic foot ulcers

Nanoengineered biomaterials have tremendously improved the range of tools utilized for the control of as well as acceleration of healing of diabetic foot ulcers (DFU) over the last few decades.

Serrulatane Diterpenoid from Eremophila neglecta Exhibits Bacterial Biofilm Dispersion and Inhibits Release of Pro-inflammatory Cytokines from Activated Macrophages

The purpose of this study was to assess the biofilm-removing efficacy and inflammatory activity of a serrulatane diterpenoid, 8-hydroxyserrulat-14-en-19-oic acid (1), isolated from the Australian medicinal plant Eremophila neglecta. Biofilm breakup activity of compound 1 on established Staphylococcus epidermidis and Staphylococcus aureus biofilms was compared to the antiseptic chlorhexidine and antibiotic levofloxacin. In a time-course study, 1 was deposited onto polypropylene mesh to mimic a wound dressing and tested for biofilm removal. The ex-vivo cytotoxicity and effect on lipopolysaccharide-induced pro-inflammatory cytokine release were studied in mouse primary bone-marrow-derived macrophage (BMDM) cells. Compound 1 was effective in dispersing 12 h pre-established biofilms with a 7 log10 reduction of viable bacterial cell counts, but was less active against 24 h biofilms (approximately 2 log10 reduction). Compound-loaded mesh showed dosage-dependent biofilm-removing capability. In addition, compound 1 displayed a significant inhibitory effect on tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) secretion from BMDM cells, but interleukin-1 beta (IL-1β) secretion was not significant. The compound was not cytotoxic to BMDM cells at concentrations effective in removing biofilm and lowering cytokine release. These findings highlight the potential of this serrulatane diterpenoid to be further developed for applications in wound management.

Inhibition of Rho-associated kinases disturbs the collective cell migration of stratified TE-10 cells

Background

The collective cell migration of stratified epithelial cells is considered to be an important phenomenon in wound healing, development, and cancer invasion; however, little is known about the mechanisms involved. Furthermore, whereas Rho family proteins, including RhoA, play important roles in cell migration, the exact role of Rho-associated coiled coil-containing protein kinases (ROCKs) in cell migration is controversial and might be cell-type dependent. Here, we report the development of a novel modified scratch assay that was used to observe the collective cell migration of stratified TE-10 cells derived from a human esophageal cancer specimen.

Results

Desmosomes were found between the TE-10 cells and microvilli of the surface of the cell sheet. The leading edge of cells in the cell sheet formed a simple layer and moved forward regularly; these rows were followed by the stratified epithelium. ROCK inhibitors and ROCK small interfering RNAs (siRNAs) disturbed not only the collective migration of the leading edge of this cell sheet, but also the stratified layer in the rear. In contrast, RhoA siRNA treatment resulted in more rapid migration of the leading rows and disturbed movement of the stratified portion.

Conclusions

The data presented in this study suggest that ROCKs play an important role in mediating the collective migration of TE-10 cell sheets. In addition, differences between the effects of siRNAs targeting either RhoA or ROCKs suggested that distinct mechanisms regulate the collective cell migration in the simple epithelium of the wound edge versus the stratified layer of the epithelium.

Electronic supplementary material

The online version of this article (doi:10.1186/s40659-015-0039-2) contains supplementary material, which is available to authorized users.

Nanomaterials for wound healing: scope and advancement

Innovative methods for treating impaired and hard-to-heal wounds are needed. Novel strategies are needed for faster healing by reducing infection, moisturizing the wound, stimulating the healing mechanisms, speeding up the wound closure and reducing scar formation. In the past few years, nanotechnology has been constantly revolutionizing the treatment and management of wound care, by offering novel solutions which include but are not limited to: state-of-the-art materials, so called 'smart' biomaterials and theranostic nanoparticles. Nanotechnology-based therapy has recently announced itself as a possible next-generation therapy that is able to advance wound healing to cure chronic wounds. In this communication, the recent progress in advanced therapy for cutaneous wound healing during last 5 years using a nanotechnology-based approach is summarized.

The role of nanotechnology in control of human diseases: perspectives in ocular surface diseases

Nanotechnology is the creation and use of materials and devices on the same scale as molecules and intracellular structures, typically less than 100 nm in size. It is an emerging science and has made its way into pharmaceuticals to significantly improve the delivery and efficacy of drugs in a number of therapeutic areas, due to development of various nanoparticle-based products. In recent years, there has been increasing evidence that nanotechnology can help to overcome many of the ocular diseases and hence researchers are keenly interested in this science. Nanomedicines offer promise as viable alternatives to conventional drops, gels or ointments to improve drug delivery to the eye. Because of their small size, they are well tolerated, thus preventing washout, increase bioavailability and also help in specific drug delivery. This review describes the application of nanotechnology in the control of human diseases with special emphasis on various eye and ocular surfaces diseases.

State-of-the-art of 3D cultures (organs-on-a-chip) in safety testing and pathophysiology

Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs--liver, lung, skin, brain--are presented and characterized in dedicated chapters. Also, 3D approaches to the modeling of tumors are presented and discussed. All chapters give a historical background, illustrate the large variety of approaches, and highlight up- and downsides as well as specific requirements. Moreover, they refer to the application in disease modeling, drug discovery and safety assessment. Finally, consensus recommendations indicate a roadmap for the successful implementation of 3D models in routine screening. It is expected that the use of such models will accelerate progress by reducing error rates and wrong predictions from compound testing.

Activation of the δ-opioid receptor promotes cutaneous wound healing by affecting keratinocyte intercellular adhesion and migration

BACKGROUND AND PURPOSE

In addition to its analgesic functions, the peripheral opioid receptor system affects skin homeostasis by influencing cell differentiation, migration and adhesion; also, wound healing is altered in δ-opioid receptor knockout mice (DOPr^–/–). Hence, we investigated δ-opioid receptor effects on the expression of several proteins of the desmosomal junction complex and on the migratory behaviour of keratinocytes.

EXPERIMENTAL APPROACH

Expression levels of desmosomal cadherins in wild-type and DOPr^–/– mice, and the morphology of intercellular adhesion in human keratinocytes were analysed by immunofluorescence. To investigate the δ-opioid receptor activation pathway, protein expression was studied using Western blot and its effect on cellular migration determined by in vitro live cell migration recordings from human keratinocytes.

KEY RESULTS

Expression of the desmosomal cadherins, desmogleins 1 and 4, was up-regulated in skin from DOPr^–/– mice, and down-regulated in δ-opioid receptor-overexpressing human keratinocytes. The localization of desmoplakin expression was rearranged from linear arrays emanating from cell borders to puncta in cell periphery, resulting in less stable intercellular adhesion. Migration and wound recovery were enhanced in human keratinocyte monolayers overexpressing δ-opioid receptors in vitro. These δ-opioid receptor effects were antagonized by specific PKCα/β inhibition indicating they were mediated through the PKC signalling pathway. Finally, cells overexpressing δ-opioid receptors developed characteristically long but undirected protrusions containing filamentous actin and δ-opioid receptors, indicating an enhanced migratory phenotype.

CONCLUSION AND IMPLICATIONS

Opioid receptors affect intercellular adhesion and wound healing mechanisms, underlining the importance of a cutaneous neuroendocrine system in wound healing and skin homeostasis.

LINKED ARTICLES

This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2